Answer:
-0.75 m
Explanation:
The displacement of the girl is given by x = x₀cosωt where x₀ = maximum displacement of swing = 1.5 m, ω = angular frequency = π/3 rad/s and t = time of swing = 4 s
Substituting the values of the variables into the equation, we have
x = x₀cosωt
x = (1.5 m)cos(π/3 rad/s × 4 s)
x = (1.5 m)cos(2π/3)
x = (1.5 m)cos120°
x = 1.5 m × -0.5
x = -0.75 m
So, the girl is 0.75 m to the left of the equilibrium position 4 seconds into the motion.
In April 1974, Steve Prefontaine completed a 10.0 km race in a time of 27 min , 43.6 s . Suppose "Pre" was at the 7.71 km mark at a time of 25.0 min . If he accelerated for 60 s and then maintained his increased speed for the remainder of the race, calculate his acceleration over the 60 s interval. Assume his instantaneous speed at the 7.71 km mark was the same as his overall average speed up to that time.
Answer:
0.18 m/s²
Explanation:
The total time taken to cover a 10 km race is 27 min, 43.6 seconds.
At 25 min, Pre was at 7.71 km mark. Therefore the average speed = 7.71 km / 25 min = 7710 m / (25 * 60) s = 5.14 m/s
The distance remaining = 10 km - 7.71 km = 2.29 km = 2290 m
The remaining time = 27 min, 43.6 seconds - 25 min = 2 min 43.6 second = 163.6 seconds
She accelerates for 60 seconds, therefore the distance covered (S) during the acceleration (a) is:
S₁ = 5.14(60) + 0.5a(60)² = 308.4 + 1800a
She maintains the speed for the remaining distance (S₂). The remaining time = 163.6 seconds - 60 seconds = 103.6 seconds. The final speed after the acceleration = (5.14 + 60a) m/s
S₂ = (5.14 + 60a)* 103.6 = 532.5 + 6216a
S₁ + S₂ = 2290 m
(308.4 + 1800a) + (532.5 + 6216a) = 2290
8016a + 840.9 = 2290
8016a = 1449.1
a = 0.18 m/s²
As Courtney switches on the TV set to watch her favorite cartoon, the electron beam in the TV tube is steered across the screen by the field between two charged plates. If the electron experiences a force of 3.0 * 10^6 N, how large is the field between the deflection plates?
Answer:
Explanation:
Force= (q1q2)/(4/\Ęr2)
3×10^6= (1.602×10^-19)^2/(r^2)
r^2=(2.27×10^-33)/(3×10^6)
r^2=8.55×10^-45
r= 9.25×10^-23
A rope horizontally pulls a massive object lying on a surface with friction with a constant
velocity. What describes the force on the rope?
Answer:
Equal to the frictional force
Explanation:
Question; The options given with regards to a similar question posted online are;
A. Equal (equivalent) to the frictional force
B. Larger than the frictional force
C. Equal to the object's weight
D. More than the object's weight
Explanation
According to Newton's first law of motion, every object shall remain at rest or continue moving with uniform (constant speed) motion unless there is a net force acting on the object
Given that the velocity of the massive block, lying on the surface that has friction, being pulled by the rope = Constant
Therefore;
The net force acting on the moving block while being pulled by the rope = 0
From which we have;
The pulling force = The resistive force
Where;
The pulling force = The (pulling) force (applied) on the rope
The resistive force = The frictional force of the surface which tends to prevent the motion of the block
Therefore, given that the net force acting on the block = 0
The force on the rope = The frictional force (of the surface)
The correct option is option A. Equal to the frictional force.
Which wave shows the loudest sound below?
Answer:
I think C
Explanation:
If im right give brainliest :)
Which one of the following is an example of a solution?
a. Sand particles in water
b. Orange Squash
c. Vinegar
d. Paint
Answer:
it is maybe A but i'm not 100% sure
Explanation:
its the only one that is mixed
what is parking orbit?
Answer:
A temporary orbit in which a spacecraft awaits the next phase of its mission .
Vector B has components Bx = 6.18 and By = 4.43. Find the magnitude and direction counter clockwise from the positive x-axis.
Answer:
Explanation:
The formula for the magnitude of this resultant vector, which is in Q1, btw, is:
[tex]B_{mag}=\sqrt{6.18^2+4.43^2}[/tex] which gives us, to 3 sig fig's:
7.60 m. Since the resultant vector is in Q1, we don't need to add anything to the angle once we find it to 3 sig fig:
[tex]tan^{-1}(\frac{4.43}{6.18})[/tex] gives us an angle of 35.6 degrees
The velocity of sound in a medium increases with increasing
a. distance
b. amplitude
c. temperature
d. time
c- temperature
The speed of sound increases with increasing temperature .
help please!!
From the following images shown, classify the interactions that occur and say between which bodies, according to the following criteria:
a) Contact forces
b) Non-contact forces
Answer:
B= 4 A=5
Explanation:
Mrs. Botts applies brakes on a car help it to decelerate at the rate of -0.80m/s2. What distance is required to stop the car when it is moving 17 m/s.
Answer:
Explanation:
vf=0
vi = 17
a = -0.8
Δx = ?
vf^2 = vi^2 + 2 a Δx
Δx = (vf^2 - vi^2) / 2a
Δx = (0-17^2) / 2 (-0.8)
Δx = 180.625 m
10 points
Calculate the force of attraction between the moon and the earth, if their masses and distance apart are 10^22Kg, 10^24kg and 6.4x10^6m. Take g = 6.67x10^-11Nm^2Kg^-2
a) 0.63x10^24N
b) 1.63x10^22N
c) 2.63x10^20N
d) 3.63x10^18N
Answer:
Explanation:
You didn't fill in the proper masses which is why you never got an answer to this. But that's ok...I got you. I happen to know what they are! We will use the universal law of gravitation and the gravitational constant to solve this.
[tex]F_g=\frac{Gm_1m_2}{r^2}[/tex] and filling in:
[tex]F_g=\frac{(6.67*10^{-11})(5.98*10^{24})(7.36*10^{22})}{(3.84*10^8)^2}[/tex] The denominator is the radius of the earth plus the radius of the moon plus the distance between their surfaces, just FYI.
That gives us that
[tex]F_g=1.99*10^{20}N[/tex] Not sure what your choices entail, but I'd have to say, taking into consideration that maybe your problem didn't figure in the distance between the surfaces, you'd be at choice B.
(I have 2 questions which are very similar)
Which of the chemical reactions above stores energy?
A. Cellular respiration
B. Photosynthesis
C. Both cellular respiration and photosynthesis
D. Neither cellular respiration nor photosynthesis
15 Which of the chemical reactions above releases energy?
A. Cellular respiration
B. Photosynthesis
C. Both cellular respiration and photosynthesis
D. Neither cellular respiration nor photosynthesis
(help!!!) SCIENCE
Answer:
B
A
Explanation:
please mark as brainliest :)
The motor of a battery-powered scooter can maintain a speed of 5.3 m/s by providing a force of 280 N. What is the power output of the motor? *
Answer:
the power output P = 1484 W
Explanation:
Power P = Force× speed
Given that motor of a battery-powered scooter can maintain a speed of 5.3 m/s by providing a force of 280 N.
Therefore,the power output of the motor P = 280×5.3 = 1484 W
Hence, the power output P = 1484 W
(b) During one day, 250 kg of water is pumped through
the solar panel. The température of this
water rises from 16°C to 38°C.
The water absorbs 25% of the energy incident on the solar panel. The
specific heat capacity
of water is 4200J/(kg °C).
Calculate the energy incident on the solar panel during that day.
Please explain how to find the incident energy
Answer: The energy incident on the solar panel during that day is [tex]9.24 \times 10^{7} J[/tex].
Explanation:
Given: Mass = 250 kg
Initial temperature = [tex]16^{o}C[/tex]
Final temperature = [tex]38^{o}C[/tex]
Specific heat capacity = 4200 [tex]J/kg^{o}C[/tex]
Formula used to calculate the energy is as follows.
[tex]q = m \times C \times (T_{2} - T_{1})[/tex]
where,
q = heat energy
m = mass of substance
C = specific heat capacity
[tex]T_{1}[/tex] = initial temperature
[tex]T_{2}[/tex] = final temperature
Substitute the values into above formula as follows.
[tex]q = 250 kg \times 4200 J/kg^{o}C \times (38 - 16)^{o}C\\= 250 kg \times 4200 J/kg^{o}C \times 22^{o}C[/tex]
As it is given that water absorbs 25% of the energy incident on the solar panel. Hence, energy incident on the solar panel can be calculated as follows.
[tex]\frac{25}{100} \times q = 250 kg \times 4200 J/kg^{o}C \times 22^{o}C\\q = 9.24 \times 10^{7} J[/tex]
Thus, we can conclude that the energy incident on the solar panel during that day is [tex]9.24 \times 10^{7} J[/tex].
Multiplying a vector with another vector results in what type of answer.
A) a direction
B) a vector
C) either a vector or a scalar
D) a scalar
multiplication of two vectors yields a vector oroduy
a bell rings at a frequency of 75hz on a warm 25 degree evening. calculate the...
a. speed of the sound wave at this temperature.
b. wavelength of the sound wave
Answer:
Explanation:
We need 2 different equations for this problem: first the velocity of sound equation, then the frequency of the sound equation.
The velocity of sound is found in:
v = 331.5 + .606T
We need to find that first in order to fill it into the frequency equation which is
[tex]f=\frac{v}{\lambda}[/tex] where v is the velocity we will find the part a, f is frequency and lambda is the wavelength. Starting with the velocity of the sound:
v = 331.5 + .606(25) and
v = 331.5 + 15 and rounding correctly using the rules for sig fig when adding:
v = 347 m/s
Filling that into the frequency equation:
[tex]75=\frac{347}{\lambda}[/tex] and
[tex]\lambda=\frac{347}{75}[/tex] so
[tex]\lambda=4.6m[/tex]
the use of thermostat in a gas cooker is to
Explanation:
An oven thermostat regulates the temperature inside an oven. The thermostat's temperature-sensitive probe measures the oven's warmth, switching the heat on and off as necessary to maintain the correct temperature.
If a train traveled 400 miles north and traveled back 275 miles south and the total trip took 5 hours to complete, what was the average velocity of the train in mph?
The average velocity is 25 mph north.
Average velocity = displacement/time
Displacement =
(400 mi north) + (275 mi south)
Displacement = 125 mi north
Average V = (125 mi north) / 5 hours.
Average V = 25 mph north
Bones are composed of three main components, what are they? (Choose all that apply)
Answer:
funny bone and compact bone
Explanation:
your funny bone only reacts if you hit it against something the compact bone is the heaviest and strongest bone in your body and the bone marrow is soft sponge like tissue in the center if most bones that produces white and red blood cells
How is an ammeter connected in a circuit to measure current flowing through it?
Answer:
It is connected in series with the circuit
Explanation:
This is because to measure the current in the circuit, the current in the circuit has to flow through the ammeter. As such, the ammeter must be connected in series with the circuit so as to measure the current flowing through the circuit.
So, to measure the current flowing through a circuit with an ammeter, the ammeter must be connected in series with the circuit.
(b) How much energy must be supplied to boil 2kg of water? providing that the specific latent heat of vaporization of water is 330 kJ/kg.
Complete question:
(b) How much energy must be supplied to boil 2kg of water? providing that the specific latent heat of vaporization of water is 330 kJ/kg. The initial temperature of the water is 20 ⁰C
Answer:
The energy that must be supplied to boil the given mass of the water is 672,000 J
Explanation:
Given;
mass of water, m = 2 kg
heat of vaporization of water, L = 330 kJ/kg
initial temperature of water, t = 20 ⁰C
specific heat capacity of water, c = 4200 J/kg⁰C
Assuming no mass of the water is lost through vaporization, the energy needed to boil the given water is calculated as;
Q = mc(100 - 20)
Q = 2 x 4200 x (80)
Q = 672,000 J
Q = 672,000 J
Q = 672,000 J
Therefore, the energy that must be supplied to boil the given mass of the water is 672,000 J
You can do only number 1 only
For 1000 seconds , a current of 0.1 A flows so as to transfer charge of 100C
A cyclist is taking part in the Tour de France, which is a bicycle race that takes place every year.
a Two forces acting on the cyclist are weight and reaction. Name two other forces acting on him
as he cycles along.
a man runs 1200m on a straight line in 4 min . find his velocity.
Answer:
5m/sec^2
Explanation:
Distance=1200m
Time=4 min
1=60sec
4=4 x 60
=240sec
Velocity=Distance/Time
Velocity=1200/240
Velocity=5m/sec^2
Mark me as brainliest
what are scalar quantities and list their examples
Explanation:
these are quantities that have magnitude but no direction
Examples include : speed, mass, volume, density, everything, time
goodie morning
—————————
what is nitric acid?
Answer:
Nitric acid, also known as aqua fortis and spirit of niter, is a highly corrosive mineral acid. The pure compound is colorless, but older samples tend to acquire a yellow cast due to decomposition into oxides of nitrogen and water. Most commercially available nitric acid has a concentration of 68% in water.
Explanation:
Good morning...
Nitric acid production is mainly driven by fertilizer industry. Nitric acid is used in the production of ammonium nitrate and calcium ammonium nitrate which find applications as fertilizers.
The energy of an electromagnetic wave changes proportionally to which
other property?
O A Speed
O B. Shift
O c. Wavelength
O D. Frequency
Answer:
D. Frequency
Explanation:
The energy of an electromagnetic wave is proportional to frequency, mathematically it is expressed as;
E ∝ f
E = hf
where;
h is Planck's constant = 6.626 x 10⁻³⁴ Js
The equation above can also be expanded to;
[tex]E = hf = h \frac{c}{\lambda}[/tex]
where;
c is speed of light = 3 x 10⁸ m/s
λ is the wavelength of the electromagnetic wave
Since the speed of light is constant, we can conclude that the energy of the electromagnetic wave is directly proportional to its frequency and inversely proportional to its wavelength.
Therefore, the correct option for direct proportionality is FREQUENCY
